Mechanical stoker.



A. G. ELVIN.

MECHANICAL STOKER. APPLICATION FI'LED r1112. 24, 1913.

Patented Sept. 22, 1914 3 SHEETS-SHEET l.

-FIG-1:-

INVENTOR 1 1 2 m 3 an H m3 m A.

A. G. ELVINt v MECHANICAL STOKER.

APPLICATION FILED M324. 1913.

Patented Sept. 22, 1914.

3 SHEETS-SHEET 2.

A. G. ELVIN.

MECHANICAL STOKER.

APPLICATION FILED FEB.24,1913.

Patented Sept. 22, 1914.

a SHEBTSSHEBT 3.

mmnum FIG 4 WITNESSES I To all whom it may concern UNITE snares PATENT OFFICE.

ALBERT G. ELVIN, 0F SOMEBVILLE, JERSEY.

' MECHANICAL STOKER.

Specification of Letters Iatent.

Be it known that I, ALBERT G. ELVIN, of Somerville, in the county of Somerset and State of New Jersey, have invented a certain new and useful Improvement in Mechanical I Stokers, of which improvement the. following is a specification.

My invention relates to appliances for feeding fuel to locomotive and other steam boiler furnaces, in which the members which act directly upon the .fuel are in the form of fuel carrying and throwing shovels, moving about vertical axes, adjacent to a firing opening in the furnace, as generally exemplified in Letters Patent ofthe United States No.v 1,058,356, granted and issued to meunder date of April 8, 1913.

The object of my present inventionis to provide means, of simple and inexpensive is a rear view, partly in elevation and partly in section on the line a a of Fig. 2, of a mechanical stoker embodying my invention, attached to the back head of a locomotive boiler; Fig. 2, a horizontal section on the line b 31 0f Fig. 1; Fig. '3, a plan or top view; Fig. 4:, a vertical longitudinal central section; Fig. 5,- a side view, in elevation, and

on an enlarged scale, of the operating cam; and, Fig. 6, a transversesection through the same, on the line 0 c of Fig. 5.

My invention is designed and adapted for operation in connection with a suitable source of fuel supply, a conveyer for transferring fuel therefrom to a location of deposit adjacent to a firebox, and an elevator for raising the fuel therefrom to a level at which the action of the mechanism herein after set forth for projecting into the fire box can be properly exerted upon it. Instances of these appliances are exemplified in Letters Patent No. 1,058,356 aforesaid,

and these, or any other suitable appliances of such character, may be employed in connection with my present invention. These, however, do not constitute part thereof, and

will not, therefore, be herein at length described.

known manner. shovel box is fully open to the. firingopen ashovel box or casing, 9, which is-bolted at its front end to, and supported by, a bracket, 9, se cured to the rear head of a firebox, Z), and is supplied with fuel in any suitable The forward side. of the ing, 6, of the firebox,cnear the lower side,

of said opening, so as to leai e as-much asv tion. Bythe usual manipulation of said doors by-a hand lever, 10, manual firing can be operated, if it should, at any time, become necessary or desirable to intermit the operation ofthe mechanism of my invention.

The fuel-which is supplied to the shovel box is gathered up therein, in successive portions or charges, and carried forward and projected into the firebox, 6, through the firing opening, I), by swinging movements of two fuel carrying and throwing shovels, each comprising a stock or body, 11, and a blade, 11, of stout sheet metal, which is curved longitudinally and curved or bent transversely, thereby enabling the shovel to receive and carry in its movements, a charge of fuel, in the manner of an ordinary fire-' Patented Sept. 22, 1914..

either horizontal or slightly inclined, as may be deemed best adaptable to the position of the rear head of the firebox, which in some cases is vertical, and in others, forwardly and upwardly inclined. The axes of the shovelshafts may therefore be stated to be located in a substantially vertical plane. In the outward or feeding traverses of the shovels, in each of which they carry a charge of fuel, they are. swung comparatively rapidly, and their inward or return traverses are effected comparatively slowly. The mechanism by which the shovels are so operated will now be described,

A segmental. spur gear, 12, is fixedupon each of the shovel shafts, below the bottom of the shovel box, said gears engaging corre sponding gears, 25 fixed on the upperends of two intermediate "shafts, 25, which are journaled, parallel with the shovel shafts, in bearings, 26, on a frame, 27, fixed to the I '32, mounted in bearings, 33, on the bottom of the frame, 27, the axial line of said shaft being located parallel with, and midway between, the pitch lines of the racks, 28. The

rollers, 30, are provided for the purpose'of reducing friction in the engagement of the racks with the cam groove, which engage ment could, of course, be directly effected, if desired, by fitting the'stems of said rollers in the groove. The cam shaft is rotated by a small motor (not shown), which is 10- cated in anyconvenient position ad'acent to the boiler head, and may desirably 'oftl'ie type set forth in Letters 'Patent' bf the United States No. 1,050,528,-granted and is sued to me under date of J anuary' 14, 1918, or may be of-any other. suitable'and preferred form, and which does n'ot form part ,of my present invention. In the instance shown, rotation is imparted to the camshaft through a chain, 3%, engaging the'teeth of a portion; and a relatively longer sprocket, 34, fixed upon theca'mshaft, and

a similar sprocket on the driving shaft of the motor. a

As will clearly appear by reference to Figs. 5 and 6 of the drawings, the c am groove, 31, is formed in the carn'in such angular relation to the axis'thereof that the major portion of said groove, as Say, about two thirds of, its projected length, is perpendlcular ,to said axis; a relatively shorter portion of the remainder of its projected length is inclined, relatively to sald major portion of the remainder of its projected ength extends, with-an opposite inclination, and at a lesser angle, from said smaller portion to the major-portion first specified. It therefor follows that, in the rotation of the cam, a member engaged with the cam groove will remain stationary while theportion of said groove which is perpendicularto the axis of the cam is passing it; will be moved in one direction, comparatively rapidly, while the shorter; inclined portion is passing it; and will be moved in the opposite direction, comparatively slowly, while the longer inclined )ortion is passing it, the periods of rest, of elatively quick movement in one direction, vnd of relatively slow movement in the oposite direction, being successive, in the orer stated. ,In the operation of a mechanical stoker nbodying my invention, a proper supply of 51101, being delivered to the shovel box, and

the motor of the cam shaft being rotated at such speed as will effect the rate of firing desired, each member of the pair of shovels termediate connections described, be swung from the rear to the front terminal of its stroke, with comparative rapidity, effecting its outward stroke, in which it Wlll [upon the horizontal portion of its blade, a charge offuel, carry said charge forwardly, and throw it into and-toward one side of the firebox. It will then be returned, comparatively slowly, to the rear terminal of its operation. During the described movements of one of the shovels, the other shovel will be "in'terme'diately connected with the portion of'the ca'm groove which is perpendicular to theaxis of the cam, and will remain stationary. When the shovel first referred to has reached the rear terminal of, its stroke, the other shovel will, by the rotation ofth'e' cam, be brought, successively, into inclined portions; of the cam groove, and will be swun first forwardly and then rearwardly, :similarly to the shovel first de-' scribed, and will similarly operate, except that it will throw the fuel toward the opposite side of the firebox. The alternate operations of the shovels will continue during the rotation of the motor, and the supply of fuel variations of the speed of the motor. 4 Among the practical advantages attained its adaptability for application, Within small compass, and in connection with any we and delivering mechanism, for service with any of the various forms of steam boiler and other fireboxes or furnaces; its structural and operative simplicity and inexpensiveness; and the connection of a pair of fuel carrying and throwing shovels with an actu ating motor in such manner that the travproper sequence, at greater and lessspeeds when feeding and returning, respectively, and without the possibility of interference of one of them with the other. i

I claim as my invention and desire to secureby Letters Patent:

1. In a mechanical stoker, the combination of a shovel shaft movable'about a vertical axis, a fuel shovel fixed on said shaft, a rotatable grooved operating cam, a rackfitted to reciprocate parallel with the axisof said cam and engaging the groove thereof, an in termediate shaft parallel with. the shovel shaft, and gearing connecting said intermediate shaft with the rack and with the shovel shaft, respectively.

2. In a mechanical stoker, the combination of a receptacle, two shovel shafts, inde- 'ather,

stroke, in readiness for a succeeding similar ferred form of fuelv conveying, elevating,

will, through the operating cam and the inconnection with the'longer and the shorter to the firebox may be regulated as desired by by my invention, there may be enumerated erses of each of them will be effected in 'pendently movable about vertical axes in said receptacle, two shovels, each fixed on one offsaid shafts,-a rotatable grooved operatin cam journaled intermediate of and at a right angle to the shovel shafts, under said receptacle andin rear of said shafts, members fitted to reciprocate parallel with and on opposite sides of the axis of the cam, each engaging the groove thereof, and intermediate connections independently transmitting movement from said members to the shovel shafts;

In amechanical stoker, the combination of two shovel shafts, independently movable about vertical axes, two fuel shovels,'- each fixed on one of said shafts, a rotatable grooved operating cam journaled intermediate of and at a right angle to the shovel shafts, members fitted to reciprocate parallel with andon opposite sides of the axis of the cam, each engaging the groove thereof,

and intermediate connections independently transmitting movement from said members to the shovel shafts. Y

4. In a mechanical stoker, the combination of two horizontally swinging shovels mounted on vertical shafts at opposite sides of the furnace opening, a rotatable cam cylinder having a groove with inclined porsteep angle and another portion inclined in the opposite direction at a lesser angle, racks having projections engaging said groove,

said racks and the shovel shafts.

ALBERT G. ELVIN.

Witnesses:

JOHN L. MoHUN, F. W. MARTIN.

and intermediate gear mechanism between 

